Yvonne Heap, who died after being stabbed outside an Oxford police station, was due to have been a witness at a close friend's wedding on May 1.

Nara Taghiyeva, 27, described Ms Heap as "an angel" who had stood by her at the most difficult time of her life.

She had invited Ms Heap to be her witness when she weds tomorrow, and to be godmother in a month's time at the christening of her son who was born in January.

The women worked together at the Ladbrokes bookmakers in Hollow Way, Cowley, Oxford, a short distance from Sunnyside, where Ms Heap, 38, had lived before moving out a few weeks ago.

Miss Taghiyeva said: "It is the world's loss. She had the kindest heart. She always thought about others first.

"I'm still getting over what has happened. She was my best friend.

"All her colleagues are devastated. She's an angel."

Miss Taghiyeva, of Cowley, got a part-time job at Ladbrokes shortly after coming to Britain from Russia about three years ago to study at Oxford Brookes University.

But she fell pregnant and split up with her former boyfriend. She had been in two minds about continuing with the pregnancy, and thanks Ms Heap for helping her.

Ms Heap was found in a blue Citroen car outside Cowley police station on Saturday afternoon with stab wounds to her heart, torso and face. She died in hospital on Monday. She had three children.

Ms Heap's former partner, Nahed Akhter, 40, known as Hector, of Sunnyside, has been charged with her attempted murder.